The present invention relates to articles of commerce comprising at least one personal care article and a package therefore where at least one of the personal care article and the package comprise a magnetic member. In preferred embodiments, the thermoplastic magnet has a three dimensional profile which enables a matched pair of the magnets to both magnetically and mechanically interact.
Magnetic materials, including magnetic materials comprising a thermoplastic, are well known. One use of such materials is as a part of a closure system (e.g., a woman's purse with a magnetic catch). Typically, such magnetic materials in conventional closure systems are in the form of rigid metal magnets or flexible magnetic tapes that are attached to articles through various mechanical and/or adhesive means. See, for example, U.S. Pat. Nos. 4,200,547 and 6,312,795 published U.S. Pat. Application Publications Nos. US 2003/0132276 and US 2005/0015069.
Such closure systems have various problems with respect to use in a personal care article. For example, the cost of the equipment necessary to position, attach (and, if necessary, cut) a flexible, bonded magnetic material to the product can be excessive. Further, such magnetic materials are limited in shape availability or other desirable properties for use in a personal care article. For example, metallic magnets are available in many shapes but are relatively expensive, particularly for application to a single use personal care article. Further, such metallic magnets have limited mechanical flexibility which is also desirable for many personal care articles.
On the other hand, flexible materials of the art are typically manufactured using a calendering process or extruded in a ribbon form. As will be recognized, such processes result in a substantially planar two dimensional form for the flexible magnetic materials. As will also be recognized, such two dimensional form can be cut into a shaped configuration by known methods, such as die cutting. However, since the magnetic material is formed in a separate step such material, even if it is somewhat flexible still needs to be applied to a substrate for use in many personal care articles. As is well known, the apparatus (e.g., cut and slip technology) for such application for single use personal care articles is both mechanically complex and expensive. It is also necessary to provide means (e.g., an adhesive) to attach the magnetic material to the substrate.
Three dimensional structures are also known where a polymer magnetic particle blend is injection molded to form an article. However, such preformed structures also must be placed and adhered to a substrate using additional manufacturing steps similar to those discussed above for application of flexible magnetic materials.
Printing magnetic materials is also known. However, such printed materials are said to comprise a magnetic ink where magnetic particles are dispersed in a vehicle and printed onto a substrate using known techniques such as screen printing. As will be recognized printing processes carry the burden of environmental undesirability due to the generation of volatile organic carbon and other effluents. Also, the presence of a vehicle limits the concentration of magnetic particles that may be incorporated into the ink due to the increase in viscosity as solids level increases with the resulting need to provide enough vehicle to maintain a printable composition (As will be recognized, the vehicle is then evaporated in a separate drying/curing step).
Thus there is a need for improved personal care articles and articles of commerce comprising such personal care articles in suitable packaging where either the personal care article or the packaging is provided with a magnetic feature.
There is a further need for magnetic features with a high magnetic flux density that can be applied to a substrate using relatively simple process apparatus such a printing.
There is still a further need for flexible magnetic features that have a relatively complex three dimensional configuration so as to provide added benefits to users of personal care articles (e.g., improved conformity to an underlying complex three dimensional shape or mechanical interlocking of a matched pair of magnetic elements).
In one embodiment the present invention comprises a personal care article of commerce, where the article of commerce comprises at least one personal care article and a package therefore. The article of commerce also comprises a magnetic member which comprises a thermoplastic material with magnetic particles dispersed therethrough. The thermoplastic material comprises a resin selected from the group consisting of polyolefins, thermoplastic elastomers, polyamides, polyacetals, polyethers, polyesters, polyurethanes, poly (meth) acrylates; and compatible mixtures of more than one thermoplastic material and the magnetic particles are selected from the group consisting of magnetoplumbite-structure ferrite particles and rare-earth magnet particles and mixtures of magnetic particle types.
A second embodiment of the present invention is a thermoplastic magnet having a three dimensional profile. The thermoplastic magnet comprises the same material as the magnetic member described above and has two surfaces where each point on the second surface is separated from a vertically opposed point on the first surface by a z dimension and there is at least one position on the second surface where the z dimension differs from the z dimension of a different position on the second surface.
In a third embodiment of the present invention a thermoplastic magnet that comprises the same material as the magnetic member described above is disposed on the surface of a fibrous substrate and at least a portion of the thermoplastic material penetrates beneath the surface by at least about two fiber diameters.
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the present invention, it is believed that the invention will be more fully understood from the following description taken in conjunction with the accompanying drawings, in which:
The term “article” herein includes both disposable and durable articles.
The term “disposable” is used herein to describe products which generally are not intended to be laundered or otherwise restored or extensively reused in their original function, i.e., they are intended to be discarded after fewer than about 10 uses, preferably after fewer than about 5 uses or even after a single use. It is preferred that such disposable articles be recycled, composted or otherwise disposed of in an environmentally compatible manner.
The term “durable” is used herein to describe products which generally are intended to be laundered or otherwise restored or extensively reused in their original function, i.e., preferably they are intended to be used more than about 10 times.
A “disposable absorbent article” refers herein to a device that normally absorbs and retains fluids. In certain instances, the phrase refers to devices that are placed against or in proximity to the body of the wearer to absorb and contain the excreta and/or exudates discharged from the body, and includes such personal care articles as baby diapers, baby training pants, adult incontinence articles, feminine hygiene articles, baby swim diapers, wound dressings, and the like. In other instances, the phrase refers to protective articles, such as, for example, dining bibs that have the ability to absorb food items to prevent staining of the wearer's clothing.
The term “diaper” includes but is not limited to baby diapers, baby training pants, disposable baby swim wear, and adult incontinence articles and refers to a disposable fluid-handling article generally worn by infants and other incontinent persons about the lower torso.
The term “feminine hygiene articles” refers herein to any absorbent article worn by women to absorb and contain menses and other vaginal exudates.
A “body wrap” refers herein to an article or a garment worn about the body, typically to provide some therapeutic benefit, such as, for example, pain relief, wound coverage or for holding another device or article near the body.
A “personal care article” is one intended to facilitate the care of an individual and includes but is not limited to diapers, wet wipes, feminine hygiene articles and body wraps.
The term “web” is meant herein any continuous material, including a film, foil, a non-woven fabric, a woven fabric, a foam or a combination thereof, or a cellulosic material including wood pulp, and the like, having a single layer or multiple layers.
The term “substrate” is meant herein any material, including a film, a foil, a non-woven fabric, a woven fabric, a foam or a combination thereof, or a cellulosic material including wood pulp, and the like, having a single layer or multiple layers, and suitable for application of a polymeric material on at least one surface of the “substrate.38
A “fibrous substrate” means herein a material comprised of a multiplicity of fibers that could be either a natural or synthetic material, metallic, or any combination thereof. For example, nonwoven materials, woven materials, knitted materials, cellulosic materials, and any combinations thereof.
The term “non-woven” refers herein to a fabric made from continuous filaments and/or discontinuous fibers, without weaving or knitting by processes such as carding, spun-bonding and melt-blowing. The non-woven fabric can comprise one or more non-woven layers, wherein each layer can include continuous filaments or discontinuous fibers.
A “natural material” means herein a material derived from plants, animals, insects or byproducts of plants, animals, and insects. Non-limiting examples of natural materials useful in the disposable articles include cellulosic fibers, cotton fibers, keratin fibers, silk fibers and the like. Non-limiting examples of cellulosic fibers include wood pulp fibers, hemp fibers, jute fibers, and the like. Non-limiting examples of keratin fibers include wool fibers, camel hair fibers, and the like.
The term “magnetic region” refers herein to an area of a material having a greater magnetic properties than the magnetic properties of an adjacent area of the material.
The term “thermoplastic magnetic material” refers herein to a composite material comprising a substrate with a one or more magnetic members disposed thereon.
The term '7magnetic members” refers herein to a thermoplastic material with magnetic particles dispersed therethrough.
Magnetic Members
As noted above, a magnetic member is a thermoplastic material having magnetic particles dispersed therethrough. As is well known, a thermoplastic material, when exposed to heat, softens or even melts. Such behavior facilitates manufacture of the personal care articles and magnetic members described herein and the method of production thereof also discussed herein.
Suitably, a magnetic member for of the present invention comprises between about 5% and about 60% of a thermoplastic material, preferably between about 10% and about 50%, more preferably between about 10% and about 25% of a suitable thermoplastic material as discussed below. The magnetic member also comprises between about 40% and about 95% of a thermoplastic material, preferably between about 50% and about 90%, more preferably between about 50% and about 90% of a suitable magnetic particulate material as described below. The member may also comprise minor amounts of other materials known in the art for compositions comprising a thermoplastic material such as plasticizers, antioxidants, colorants and the like.
Thermoplastic Materials
Suitable thermoplastic materials comprise those that become sufficiently fluid upon heating to allow incorporation of magnetic particulate material, for example, by extrusion mixing, kneading in a sigma mixer or by other suitable means.
In some embodiments, at least a portion of the thermoplastic material may comprise a material with substantially plastic properties. Exemplary classes of materials include, but are not limited to polyolefins, polyamides, polyacetals, polyethers, polyesters, polyurethanes, poly (meth) acrylates. Particularly preferred are polyolefins. A particularly preferred polyolefin is a polypropylene resin having melt flow rate greater than about 100 g/10 min as measured according to ASTM standard method 1238. Commercially available resins that are suitable for use as a thermoplastic component of the present invention include a high melt flow rate polypropylene available from Basell Polyolefins, Inc. of Hoofddorp, Netherlands as PRO-FAX SC973 and a polypropylene homopolymer from ExxonMobil Chemical of Houston, Tex. as PP3546G.
In some embodiments at least a portion of the thermoplastic material may comprise a thermoplastic elastomer. Such compositions comprise thermoplastic elastomers selected from the group consisting of styrenic block copolymers, metallocene-catalyzed polyolefins, polyesters, polyurethanes, polyether amides, and combinations thereof. Suitable styrenic block copolymers may be diblock, triblock, tetrablock, or other multi-block copolymers having at least one styrenic block. Exemplary styrenic block copolymers include styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene/butylenes-styrene, styrene-ethylene/propylene-styrene, and the like. Commercially available styrenic block copolymers include KRATON® from the Shell Chemical Company of Houston, Tex.; SEPTON® from Kuraray America, Inc. of New York, N.Y.; and VECTOR® from Dexco Chemical Company of Houston, Tex. Commercially available metallocene-catalyzed polyolefins include EXXPOL® and EXACT® from Exxon Chemical Company of Baytown, Tex.; AFFINITY® and ENGAGE® from Dow Chemical Company of Midland, Mich. Commercially available polyurethanes include ESTANE® from Noveon, Inc., Cleveland, Ohio. Commercial available polyether amides include PEBAX® from Atofina Chemicals of Philadelphia, Pa. Commercially available polyesters include HYTREL® from E. I. DuPont de Nemours Co., of Wilmington, Del.
Particulate Magnetic Material
The other key component of the magnetic member of the present invention is a particulate magnetic material. Suitable magnetic particulate materials include but are not limited to magnetoplumbite-structure ferrite particles and/or rare-earth magnet particles with an average particle diameter between about 0.5 and about 1.5 microns which exhibit a surface magnetic flux density of not less than 2000 Gauss after incorporation into the magnetic member. Preferably, the magnetic flux density is greater than about 3000 Gauss, more preferably greater than about 5000 Gauss. Commercially available materials include magnetoplumbite-structure ferrite particles, such as GP-300 available from Toda Kogyo Corporation of Hiroshima, Japan; HM410 available from Hoosier Magnetics Inc. of Ogdensburg, N.Y.; rare-earth magnetic particles such as MQP-B available from Magnequench Co., Ltd.) of Indianapolis, Ind. or the like. A particularly preferred material is a strontium-ferrite powder available from AMC Magnet Co. Ltd. of Anhui, China as BMS-5.
Method of Making Thermoplastic Magnetic Members
The above magnetic materials can be manufactured by a process 50 of the present invention, one embodiment of which is illustrated schematically in
The molten blend may be prepared using any of the methods discussed above. Particularly preferred is compounding using a compounding twin screw extruder such as those available from Farrell Corporation of Ansonia, Conn. The molten blend is delivered to printing device 54 using any suitable means such as slot extrusion. A doctor blade (not shown) may be used to level the blend across the width of the printing device 54.
For substrates in a fibrous form, the degree of bond strength between magnetic member 60 and either or both of substrates 34, 36 can be controlled by applying a predetermined pressure at either or both of printing device 54 and roll pair 58 to affect the contact. As described above, the substrates 34 and 36 can be any suitable fibrous. The source of the pressure can be any suitable means, including contacting or noncontacting means.
When substrate (s) 34, 34 is in a non-fibrous form pressure as discussed above still has a substantial effect on bonding between magnetic member 60 and the substrate (s) because such pressure affects how completely the magnetic member contacts the surface of the web. Bond strength can be enhanced, however, through the use of bonding techniques as are known to the art. For example, thermal bonding (e.g., through the use of a heated embossed roll) can be used to remelt (or partially remelt) either or both of magnetic member 60 and substrate(s) 34, 36 so as to increase bonding therebetween. As will be recognized, the energy for such thermal bonding can also be provided by sources in addition to a heated roll. Examples include ultrasonic bonding (see e.g., U.S. Pat. No. 4,823,783) and RF (i.e., microwave) heating. Also suitable is dynamic mechanical bonding as described in U.S. Pat. No. 4,854,984 where the layers to be bonded are forwarded in a face to face relation through a pressure biased nip between a patterned nip defining member and an opposing nip defining member (e.g., a relief patterned cylinder and an anvil cylinder) which members are independently driven to maintain a predetermined surface velocity differential between them. It should also be recognized that each of these bonding methods are also suitable for use with a fibrous substrate when the fibrous substrate comprises thermoplastic fibers.
Uses of Magnetic Members
The magnetic members of the present invention can be utilized in various articles of wear and use requiring a closure system for holding the articles in place on the wearer or for providing barrier properties in packaging including, such as, lotion wipe or tissue dispensers. Such articles may be either disposable or durable. Some examples of articles utilizing the closure system of the present invention are illustrated in
Absorbent Article Component
When used as a component of a disposable absorbent article the magnetic members of the present invention provide resistance to other products that are often used in conjunction with such absorbent articles so as to maintain the functionality of the closure system of the absorbent article even if a surface of the closure system becomes contaminated. For example, baby lotion is frequently used in conjunction with changing an infant diaper. If the surface of an adhesive closure system becomes contaminated with such baby lotion, adhesive functionality may be substantially lost. On the other hand, magnetic attraction is not substantially diminished by a thin layer of baby lotion on the surface of a magnetic member so little, if any, loss of functionally of a closure system based on the magnetic members described herein would b expected.
In the embodiment of diaper 310 shown in
As can be seen most clearly in
Magnetic members according to the present invention can also be used with tab and slot closure systems as described in U.S. Pat. No. 6,251,097 as an aid in aligning the components thereof.
In an alternative embodiment, not shown, the magnetic members of the present invention can comprise one or both of the primary fastening system and the waist closure system for providing side closure and waist closure respectively as described in greater detain in U.S. Pat. No. 5,151,092. The magnetic members have a particular advantage in that they can be designed so as to have “skin friendly” body contact surfaces and still provide a force serving to maintain a diaper in a closed configuration.
In this embodiment of the present invention, closure system 430 comprises a matched of a chassis magnetic member 432 and a pair of wing magnetic members 434 disposed on each of the wings 420. As shown most clearly in
It should be noted that a plurality of absorbent articles comprising the magnetic members described above is provided with suitable packaging so as to provide an article of commerce for such personal care articles. It is believed that, when such an article of commerce is provided, the magnetic members discussed herein are more resistant to the damaging effects of compression packaging as is typically used for disposable absorbent articles. For example, compressive forces may cause reduction in the loft of the loop portion of a hook and loop fastening system causing a reduction in the efficiency thereof. Similarly, compressive packaging may cause increased adhesive forces between an adhesive member and a release liner associated there increasing the difficulty of separating the adhesive from the release liner.
Component of Durable and Non-Durable Consumer Goods
While the projections 725 are shown in
Closure mechanism 1010 may be manufactured by disposing the magnetic member which will, ultimately, become movable clasp 1014 on a fibrous substrate which will, ultimately, become a part of strap 1020 using the method described above. The magnetic member which forms clasp 1012 may also be formed on a substrate as described above and either adhesively joined to the vamp of shoe 1000 or, if desired, the substrate on which clasp 1012 has been disposed may be used as a material for production of shoe 1000.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”.
All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. To the extent that any meaning or definition of a term in this written document conflicts with any meaning or definition of the term in a document incorporated by reference, the meaning or definition assigned to the term in this written document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
This application claims the benefit of U.S. Provisional Application No. 60/692,645, filed Jun. 21, 2005.
Number | Date | Country | |
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60692645 | Jun 2005 | US |